ft.) Velocity Pressure (in. Firstly, it can help you segment the market better. Used to indicate a fan’s motor size. All you can do is measure the current fan and it is a four blade 18” fan with a 30 degree angle. The length should be expressed in feet, which may involve converting the units from meters. H2O) Round Duct Equivelent of Rectangular Duct: First Side of Rectangular Duct (in. Brake horsepower (BHP) is the amount of work generated by a motor under ideal conditions. brake horsepower: NPSH = net positive suction head: V = velocity of fluid or liquid: p = impeller inlet pressure: p v = vapor pressure of fluid or liquid: SW = specific weight of fluid or liquid: g = acceleration of gravity: References - Books: 1) P. Aarne Vesilind, J. Jeffrey Peirce and Ruth F. Weiner. CW Clockwise. A measure of power consumption. = pump delivery pressure, psia. AMCA Air Movement & Control Association. Fan Brake Horsepower: Flowrate (CFM): Static Pressure at Discharge (in. CL. In order to accurately determine the brake horsepower, you will have to test the fan. The conversion from watts to horsepower is 745.7 watts = 1 hp. 3rd ed. 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0 2 4 6 8 1012 1416 18 CFM x 100 0 0.05 0.1 0.15 0.2 0.25 0.3 Brake Horse Power Brake Horsepower Curve (CFM to BHP relationship) Again we’ll use our 2010 Camaro SS as a basis for our calculations. In our example, we’ve chosen 33,000 CFM, marked with a brown vertical line. Now let’s calculate some basic torque and horsepower numbers. Measure of fan speed. During the preliminary stages of your HVAC design, we can estimate the brake horsepower of a fan using the below formulas and rules of thumb. Open: Electric Motor Time to Start Calculator. By definition horsepower is equal to 550 ft-lb per second or 33,000 ft-lb per minute. Pump-motor horsepower calculations Horsepower calculation—US units Calculate motor horsepower for shipboard auxiliary equipment such as pumps. Brake horsepower and fan curves with direct drive motors. Brake horsepower is less than the advertised engine horsepower which excludes all loads such as water pumps, alternators, fans, transmissions, etc. Brake horsepower definition: the rate at which an engine does work, expressed in horsepower . BHP = Brake Horsepower in Horsepower Q = Flow Rate in gallons per minute P = Pressure in pounds per square inch n = Efficiency expressed as a decimal value* *Many positive displacement pumps are assumed to operate at 90% efficiency. Car and truck engines in Europe are rated in kW too. Details on fan type and control, air volume (CFM), brake horsepower, and motor nameplate horsepower for each fan in the fan system must be entered. Horsepower is a unit of measurement that calculates power. Used to describe the rotation of an impeller. It was originally coined by a Scottish engineer to compare the power of steam engines with the power of horses. D s = specific diameter, ft. EFF = pump efficiency. Watts = Horsepower × 746. H = head, (ft lb)/lb. To find the electric horsepower of a motor, use the equation: Horsepower = (Volts x Amps) / 745.7 (does not take efficiency into consideration) Example: The electric horsepower of a motor with 120 volts and 10 amps is: HP = (120 x 10) / 745.7. Used to determine the proper motor horsepower and wiring. The first level of compliance requires the proposed brake HP be less than or equal to a calculated maximum allowed brake HP. That's how we spcecify motors - output horsepower in HP (US) or kW (Euro), where 0.746kW=1 HP. Since the power delivered by engine is calculated by applying brakes, it is popularly called has brake horsepower. Another common unit of power that motors are rated in is watts. It is always best to check the specs on the fan blade before replacing the condenser fan motor on any unit, and especially on older models. Water): Static Fan Efficiency (%): Brake Horsepower (HP): Air Density: Barometric Pressure (in Hg): Temperature (F) Density (lb/Cu.ft. Motor Sizing. Horsepower on the motor nameplate is the ideal steady-State shaft horsepower to an ideal load, at ideal temperature, at ideal voltage, at full-load-amperage (FLA). Proper sizing and selection of a motor for your equipment is key to ensuring performance, reliability and cost of the equipment. In this case, the original was a four blade 18” fan with a 27 degree angle – but you don’t know that. Horsepower out is less than HP in, regardless of units. Torque is measured in pound-feet (lb-ft.) Step 1. One of my first favorite cars was an MG TD which was honest enough to list both values. The watt is also a unit of power. BHP is measured within the engine’s output shaft, and was originally designed to calculate and compare the output of steam engines. If you enter any four of these variables as inputs, the calculator will determine the fifth variable. It's Calculated hp was given as 54.4 hp, while it's delivered hp (brake hp) was given as 10.97 hp. Though horsepower units are a derivative of the 33,000 ft-lbf/min, it is not critical to understanding how to calculate motor horsepower for speed and torque. Environmental Engineering. For an electric motor, brake horse power is the mechanical horsepower available at the shaft at specified rpm and full load current. These formulas should be used as an estimate and for information only. In one of my project for selection of the pump, I know following things : (1) my motor HP required is 50 (2) my brake HP is depending on flowrate and head varies between 30-40. Since 1 HP is equal to 746 W simply multiply the horsepower by 746 for this conversion. Since motors are not 100% efficient, the number of amps needed to achieve the power output is actually higher depending on the efficiency. CFM Cubic feet per minute, the volume of air moved per minute. The class identifies the limit of the fan’s performance range. If the resistance works out to be greater than the minimum value, use the value calculated. Rotation is determined by viewing the impeller from the drive side on centrifugal fans. The Fan Laws Applied A set of mathematical relationships called the fan laws governs the pulley sizes, rpm of each pulley, and the quantity of air in cfm. Excellent question and a source of confusion for lots of new plant engineers. It is measured by the... | Meaning, pronunciation, translations and examples When calculating this, you will be able to determine the power that a fan requires theoretically, but you must be aware that the actual power that the fan requires (called brake horsepower) will always be greater than what you calculated simply because no fan can achieve perfect efficiency. This calculator can be used to determine the centrifugal pump brake horsepower (BHP) for a given flow rate (Q), head (H), specific gravity (S.G.), and efficiency (Eff). I have confusion in power calculation for the pump. HOW TO READ A FAN CURVE STEP 1 – SELECT YOUR DESIRED CFM . Other articles where Brake horsepower is discussed: horsepower: …turbine, or motor is termed brake horsepower or shaft horsepower, depending on what kind of instrument is used to measure it. Calculated out this gives an electric horsepower of 1.6092. gpm = fluid flow rate through pump. I've used the formula (measured amps divided by fla) times horsepower of motor to plot cfm on a fan curve before, but I have been questioned by a customer regarding this formula and direct drive motors. There are many different standards and types of horsepower. This work is calculated without the consideration of the effects of any auxiliary component, that may slow down the actual speed of the motor. Choose either Brushed or Brushless motor to get the most accurate result. I know that Motor HP is the indicator for power consumption/energy bill when running the pump. HBhp = hydraulic brake horsepower required by pump (pump efficiency = 1.0 for HBHP calculation) Motor Watts is the rated Watts of the motor. This calculator provides an estimate of the horsepower of an electric motor. Two common definitions used today are the mechanical horsepower (or imperial horsepower), which is about 745.7 watts, and the metric horsepower, which is approximately 735.5 … C = constant. 1994. Butterworth Heinemann. Horsepower (hp) is a unit of measurement of power, or the rate at which work is done, usually in reference to the output of engines or motors. This article will show you how to calculate the horsepower of your cars engine, an electric motor, and your own body. To calculate the size of a motor two methods can be used: The steady state method and the dynamic method. Calculate the length of the motor's lever arm from the data you have. Account for Efficiency. Also included is information on motor efficiency and horsepower calculations as well as several motor calculations for energy efficiency and electrical troubleshooting. hp Horsepower. The second curve shows the relationship between the fan’s air volume flow rate and the brake horsepower. Class of fan. Torque also has a direct influence on a vehicle's horsepower, since horsepower is simply a measure of how fast the motor's torque is being applied. Horsepower of reciprocating engines, particularly in the larger sizes, is often expressed as indicated horsepower, which is determined from the pressure in the cylinders. The speed of the tip of a fan wheel or prop measured in feet per minute. Brake horsepower (BHP) refers to the actual mechanical horsepower received at the shaft of the driven machine, such as a fan, pump, compressor, etc. If the power peak is really 5,900 rpm, how much torque is the engine generating at that engine speed? In addition to the information below for properly sizing a motor, Oriental Motor offers online motor sizing tools as well as assistance from our Technical Support staff. Motor Power is the Horsepower of the motor. Bhp Brake Horsepower. CCW Counterclockwise. TS Tip Speed. BHP Brake horsepower, the fan’s power consumption. pres. Calculating Horsepower from Torque. D = impeller diameter or rotor, ft del. Does anyone have any information regarding brake HP and direct drive motors? ): Velocity Pressure: Flowrate (CFM): Cross Sectional Flow Area (sq. Once you select your CFM, draw a line vertically up to intersect the CFM vs SP Curves that run from lower right to upper left. dynamic braking resistor selection calculation ... these calculations do not include the motor and drive losses which can easily be 10% of the motor horsepower. 1 mechanical HP is equivalent to @ 746 watts. Bhp = brake or shaft horsepower, bhp. fan laws for troubleshooting. A value of 0.9 is often used for this calculation. Its published numbers are as follows: HP = 426 bhp @ 5,900 rpm Torque = 420 ft-lbs @ 4,600 rpm. Below, I will discuss how to select a constant and variable volume fan based on our calculated brake horsepower. rpm Revolutions Per Minute. If you are a sales guy, with a good understanding of these terms, you have better chances of closing a deal, irrespective of whether you are selling or leasing cars for several reasons. 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